MODELING OF MULTI GAS-SOLID REACTIONS - EFFECT OF BULK ENVIRONMENT PARAMETERS ON SOLID CONVERSION

A unified gas-solid reaction model that considers multi gas-solid comp onents is developed for reactions in porous pellets with multiple reac tants. The transient variables and properties of the reactants and tra nsport parameters are continually updated in the simulation. Temperatu re, pressure, solid conversions, and concentration profiles are well p redicted. Structural changes are also considered. Heat, mass, and reac tion front tracking equations for all the components are solved simult aneously through a combination of solution techniques. Illustrative va lidation results for the model are presented for hematite/nickel oxide reduction at 608 K. The importance of bulk temperature and pressure o n the overall and individual grain conversions is explored for a range of interest. The response of system parameters to dynamic changes in boundary conditions is studied.